Zigzag sewing mechanism



June 23, 1970 TATSUO KOZAKI 3,516,374

ZIGZAG SEWING MECHANISM Filed June 21, 1968 2 Sheets-Sheet l I HIIIIIIIIIIIII m-.. I

I km/11151! June 23, 1970 TATSUO KOZAKl ZIGZAG SEWING MECHANISM 2 Sheets-Sheet 8 Filed June 21; 1968 FIG. 2

United States Patent Q 3,516,374 ZIGZAG SEWING MECHANISM Tatsuo Kozaki, Kariya-shi, Japan, assignor to Aisin Seiki Company Limited, Kariya-shi, Japan, a corporation of US. Cl. 112158 3 Claims ABSTRACT OF THE DISCLOSURE A zigzag sewing mechanism which is provided with a stitch cam packet and a manually turnable stitch selection dial, said dial being formed rigidly with a concentric first cam and a concentric first gear, while said cam packet is provided with a second cam and a second gear concentrically and freely rotatably arranged relative to said cam packet, said second cam and gear being unitedly combined with each other and said first gear and said second gear being kept in permanent engagement with each other, said first cam having a first follower which is linkedly connected with a conventional stitch cam follower adapted for cooperation with said cam packet, while said second cam cooperates with a second follower which is rigidly united with said stitch cam follower. By manipulating said dial, the stitch cam follower is disengaged from the cam packet and shifted to a level in registration with a newly selected stitch cam belonging to said cam packet and then brought into engagement therewith, without manipulating any other manipulating means.

This invention relates to improvements in and relating to a zigzag sewing mechanism fitted on a zigzag stitch sewing machine by use of a longitudinally reciprocating and laterally oscillating needle.

In the conventional sewing machines of the above kind, a stitch selection was carried into effect in two successive steps and by means of two different manipulating means.

But, such an operation is highly troublesome and causes complaints from the side of final consumers on the market.

The main object of the present invention is therefore to obviate such two step manipulation of stitch design selection, and to unite these manipulation means into one and the same means such as a dial, knob or the like.

Starting from the conventional mechanism of the above kind, comprising a cam packet consisting of a number of stitch cams grouped in a stack, a pivotable cam follower adapted for cooperation with any selected one of said stitch cams, a needle reciprocable along its longitudinal axis and pivotable in a lateral plane, means for transmitting the oscillating movement of said cam follower caused to take place under the control of the selected stitch cam to said needle for laterally pivotal motion of the latter, and manually adjustable stitch selecting means through its follower operatively connected with said stitch cam follower for performing the stitch selection, the invention is characterized as follows: said stitch selecting means is fitted with a gear, a cam and a follower cooperating therewith, and said stitch cam packet is fitted concentrically and slidably with a selector cam and a gear part kept in mesh with said gear, a second follower is formed integrally with said stitch cam follower and kept in cooperation with said selector cam, whereby, when said manual stitch cam selecting means is manipulated to one of its selected one of operating positions, the stitch cam follower is disengaged from one of said stitch cams through the intermediary of the first mentioned cam and its follower and at the same time transferred to a newly ice selected one of said stitch cams through said selector cam and said second follower.

These and further objects, features and advantages of the invention will become more apparent when read the following detailed description of the invention by reference to the accompanying drawings illustrative of a preferred embodiment of the invention. It should be however expressly understood that the embodiment shown is only for the illustrating purpose and thus should not be construed as a definition of the invention. Therefore, several modifications which should occur to those skilled in the art upon reading the following detailed description may be included within the spirit and scope of the invention so far as they fall within its scope.

In the drawings:

FIG. 1 is a schematic sectional side view of essential parts of the sole illustrative embodiment, yet being partially omitted for simplicity of the drawing.

FIG. 2 is substantially a top plan view of essential working parts shown in FIG. 1, yet being partially omitted for simplicity.

FIG. 3 is a fragmentary and sectional view of the mechanism shown in FIGS. 1 and 2, being taking substantially along the sectional line III--III shown in FIG. 2.

FIG. 4 is an enlarged representation of a substantial part of FIG. 1.

Referring now to the accompanying drawings, numeral 10 denotes a conventional upper shaft of a Zigzag stitch sewing machine, said shaft being rotatably supported in conventional bearings one of which is shown at 11 as integral with the machine head generally shown at 12 comprising a stand 12a and an arm 12!) made integral with each other. At the righthand extremity, when seen in FIG. 1, the upper shaft 10 rigidly bears a drive pulley 13 which is drivingly connected through a V-belt 14 with a drive motor. Worm gear 15 is rigidly mounted on the shaft 10 at an intermediate point thereof and kept in meshing relation with an intermediate gear 16 which is rotatably mounted on a stationary support 17 by means of suitable bearing means, although not shown. The support 17 is integral with the machine arm 1212, although the fixing means serving for this purpose has been omitted from the drawing for simplicity thereof. The intermediate gear is kept in mesh with a drive gear 18 for a cam packet 19 consisting of a number of vertically overlapped stitch cams, generally shown at C. These cams are formed at their peripheral surfaces various and different cam undulations, as conventionally, for the lateral oscillation of a sewing needle 20, as will be more specifically described hereinafter.

A selector cam 21 is concentrically and slidably arranged relative to said cam packet 19 thereunderneath and formed on its peripheral zone with a camming undulating surface 21a having zones of different heights when seen vertically. At the lower part of the selector cam 21, there is provided a gear part 2112 which is made integral, therewith.

Numeral 22 denotes a stitch selector dial rotatably mounted at 22a on said support 17 and being formed at its lower part with a gear part 22b which is only partially shown and kept in meshing with said gear part 21b, although not specifically shown. Below the gear part 22b, there is provided an actuator cam 23 which is made integral with said stitch selector dial 22 and formed on its peripheral surface with undulations consisting of a number of camming projections 60 and recesses 61 arranged alternatively therewith. The camming projections 60 act for disengagement of a contactor 28, as will be more fully described hereinafter. From the foregoing, it will be clear that rotation of selector cam 21 may be carried into efliect by turning said dial 22.

A feeler lever 24 is pivotably mounted about its pivot 24a and kept with its curved tip end with the periphery of said actuator cam 23, said pivot 24a being studded on the stationary support 17, although the studded design is not specifically shown.

The feeler lever 24 is linked with its opposite end at 24b with a connecting rod 25 the opposite end of which is linked with an eye 26a integral with a pivotable member 26 which is pivoted at 27. This pivot pin 27 is studded on an extension 17a of the stationary member 17. Pivotable member 26 is formed integrally with a channel 26b.

On the extension 17a, there is provided an adjustable stop 35 for the member 26.

Double arm contactor 28 is formed with arms 29 and 30, a recess 31 being formed on the periphery of the contactor and receiving slidably a vertical pin 42 depending from the upper chord of a channel piece 26b integral with the pivotable member 26.

A compression spring 33 is inserted between the upper chord of said channel piece 26b and the selector cam 21 for urging the double arm contactor with its arm 30 to make pressure contact with the selector cam 21, as can be judged from FIGS. 2 and 4. The remaining arm 29 of the contactor is normally kept in pressure contact with the peripheral surface of an occasionally selected one of the generation cams C belonging to the cam packet 19. When the feeler arm 24 is brought into engagement with one of the camming projections 60, the double arm contactor 28 is disengaged from the cam packet, as will be more fully described hereinafter. Stitch cams C, selector cam 21 and stitch follower disengaging cam 23, on the one hand, and cam followers 29, 30 and 24, on the other hand, are designed and arranged as follows:

The rise of the projections on the cam 23 cooperating with its follower lever 24 is larger than the maximum rise of any one of the stitch cams C adapted for cooperation with the follower arm 29. On the other hand, the maximum rise of projections 21b on stitch selector cam 21 adapted for cooperation with follower arm 30 is so designed as to bring the stitch cam follower 29 into engagement with the uppermost one of the stitch cams C. The engagegement of the follower arm 29 with successive stitch cams C is assured by the respective engagement of cam projections on the cam 23 with its follower lever 24.

Stitch patterns generally shown at P for easy identification purpose are represented on the upper surface of the dial 22, so as to cooperate with a stationary identification mark S provided on a properly selected position on the machine arm 12b. It should be noted in this case that the mark S is shown in FIG. 2 as if it be provided on the upper surface of gear (22b), for the purpose of simplifying the drawing. By manipulating the dial 22 so as to bring any selected stitch pattern P into registration with said S, it shows that the desired stitch selection has been completed. For this purpose, the machine arm 12b is formed with a viewing window 40 which is closable by means of a pivotable cover 41. In FIG. 1, this window is shown in its closed position.

The lower end of the depending pin 42 is received in the forked upper and inner end of oscillation transmitter 43 formed into a channel member when seen in FIG. 3. The transmitter 43 is pivotably mounted at 43a around a pivot 44 which is fixedly mounted on a stationary member 45 supported rigidly by the machine head 12.

The transmitter 43 mounts at its lower part a pin 46 which is kept in cooperation with a conventional stitch adjuster 47 having an adjusting means 47a (a kind of slide). The stitch width adjuster 47 is linked with a transmission rod 48 which is linked again at 48a with a conventional needle holder 49 pivotally mounted at 49a on the inside wall of machine arm 12b. The holder 49 mounts a conventional needle 50. Stitch adjuster 42 is 4 supported through a connecting piece 51 by a stationary pin 52 which is supported on the inside wall surface of the machine stand 12a rigidly mounted on a conventional machine bed 53.

The operation of the stitch selector mechanism so far shown and described is as follows:

When the main drive motor, not shown, is brought into operation, motion is transmitted therefrom through belt 14 and pulley 13 to the upper shaft 10 which is thus rotated in the counterclockwise direction when seen in FIG. 3. In this way, the needle bar 50 carrying needle 20 is reciprocated vertically as in the conventional zigzag sewing machine.

Rotation is thus transmitted from the upper shaft 10 through worm 15, worm wheel 54 which is made integral with intermediate gear 16 and drive gear 18 to the stitch cam packet 19 which is also made integral therewith, thus all the stitch cams C being brought into rotation in the clockwise direction when seen in FIG. 2.

In the position shown, the stitch cam follower 29 is kept in engagement with the lowermost one of the cams C, as an example. But, in the drawings, especially in FIG. 2, the follower has been shown as if it be kept in engagement with the uppermost stitch cam. But, this is only for the convenience of the drawing mode and there is no other reason.

Now assuming that the machine operator desires to select the next higher stitch came under these conditions, the dial 22 is rotated a step in the clockwise direction in FIG. 2. At the half step of this manipulation, the follower 24 rises up with its motion-receiving finger end to the highest portion of the next following cam projection 60 and thus the follower lever 24 is turned in a counterclockwise direction in FIG. 2 so that the connecting rod 25 is pulled in the direction shown by the arrow A. In this way, the follower finger 29 is disengaged from the stitch cam packet through the corresponding counterclockwise rotation (see, arrow B) of the pivotable support 26 and channel piece 26b about the pivot 27 and pin 42 in slot 31 as shown in FIGS. 2 and 3. During this manipulation, the gear 22b is rotated in the clockwise direction while the mating gear 21b is rotated in a counterclockwise direction in FIG. 2, accompanying the selector cam 21. By this movement, the second follower or finger 30 will slide up along the rising cam surface of the next step projection on the selector cam 21, which means that the first follower or finger 29 is vertically shifted to the now selected next higher stitch cam C. By continuing the manipulation of the dial 22, the finger end of lever 24 will slide along the descending slope on the cam projection 60 and finally brought into engagement with the next cam recess 61. Therefore, the lever 24, connecting rod 25, pivotable member 26, channel piece 26b and contactor 28 will perform their movement in the reverse order so that the stitch cam follower :29 is brought into engagement with the now selected stitch cam, while the selector finger 30 is kept at the presently selected level.

Under these conditions, the operator can sew on the material, not shown, placed below the needle 20 the newly selected stitch design.

More specifically, oscillation is transmitted, as conventionally, from 29 through 31, 42, 43, 46, 47, 47a, 48 and 48a to 49, thence through 50 to the needle 20, for performing a lateral oscillation with the newly selected amplitude.

It should be expressly understood that the combination of selector came 21 and gear part 21b is concentrically mounted relative to the cam packet, yet in a relatively slidable manner, which construction may be well seen from a precise inspection of FIG. 1.

In other words, the gear-and-cam combination is rotatably mounted on a bearing metal which is arranged rotatably around a shaft 101 which is rigidly connected with a central shaft .102 mounting the stitch cam packet.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. In a zigzag sewing mechanism for a zigzag sewing machine, comprising a cam packet consisting of a number of stitch cams grouped in a stack, a pivotable stitch cam follower adapted for cooperation with any selected one of said stitch cams, a needle reciprocatable along its longitudinal axis and pivotable in a lateral plane, means for transmitting the oscillating movement of said cam follower caused to take place under the control of a selected one of said stitch cams to said needle for laterally pivotal motion of the latter, and manually adjustable stitch cam selecting means operatively connected with said stitch cam follower for performing a stitch cam selection, the improvement comprising a first cam connected to said stitch cam selecting means; a first gear connected to said first cam, said first cam, said first gear and said stitch cam selecting means being connected together and concentrically arranged for unitary rotation about a common longitudinal axis; a first follower mechanically cooperating with said first cam; a selector cam mounted concentrically with and slidably about said stitch cam packet; a second gear mounted concentrically with and slidably about said cam packet and integral with said selector cam; said first gear and said second gear being constantly in mesh with each other; a second follower formed integrally with said stitch cam follower and cooperating with said selector cam; and means for transmitting motion from said first follower to said stitch cam follower, whereby, when said manual stitch cam selecting means is manipulated to one of its selected operating positions the stitch cam follower is disengaged from the one of said stitch cams through the intermediary of said transmitting motion means and at the same time trans ferred to a newly selected one of said stitch cams through the action of said selector cam on said second follower.

2. A zigzag sewing mechanism as set forth in claim 1, wherein a connecting rod, a pivotable member and a pin operatively connects said first cam follower to said pivotable stitch cam follower, said member and the last mentioned cam follower being arranged to move in unison with each other so far as the pivotable motion of the last-mentioned cam follower is concerned.

3. A zigzag sewing mechanism as set forth in claim 2, wherein said pivotable member is provided with a guide pin along which said stitch cam follower is slidable.

References Cited UNITED STATES PATENTS 3,012,527 12/1961 Sternberg 112-158 3,013,512 12/1961 Yamashita 112-158 RICHARD J. SCANLAN, JR., Primary Examiner 

